Commit Graph

206 Commits

Author SHA1 Message Date
Reid Kleckner 8ff7785ee1 Remove AttributeSetNode::get(AttributeList, unsigned) and sink constructor
The getter was equivalent to AttributeList::getAttributes(unsigned),
which seems like a better way to express getting the AttributeSet for a
given index. This static helper was only used in one place anyway.

The constructor doesn't benefit from inlining and doesn't need to be in
a header.

llvm-svn: 299900
2017-04-10 23:46:08 +00:00
Reid Kleckner eb9dd5b87f Reland "[IR] Make AttributeSetNode public, avoid temporary AttributeList copies"
This re-lands r299875.

I introduced a bug in Clang code responsible for replacing K&R, no
prototype declarations with a real function definition with a prototype.
The bug was here:

       // Collect any return attributes from the call.
  -    if (oldAttrs.hasAttributes(llvm::AttributeList::ReturnIndex))
  -      newAttrs.push_back(llvm::AttributeList::get(newFn->getContext(),
  -                                                  oldAttrs.getRetAttributes()));
  +    newAttrs.push_back(oldAttrs.getRetAttributes());

Previously getRetAttributes() carried AttributeList::ReturnIndex in its
AttributeList. Now that we return the AttributeSetNode* directly, it no
longer carries that index, and we call this overload with a single node:
  AttributeList::get(LLVMContext&, ArrayRef<AttributeSetNode*>)

That aborted with an assertion on x86_32 targets. I added an explicit
triple to the test and added CHECKs to help find issues like this in the
future sooner.

llvm-svn: 299899
2017-04-10 23:31:05 +00:00
Reid Kleckner 211b1f324f Revert "[IR] Make AttributeSetNode public, avoid temporary AttributeList copies"
This reverts r299875. A Linux bot came back with a test failure:
http://bb.pgr.jp/builders/test-clang-i686-linux-RA/builds/741/steps/test_clang/logs/Clang%20%3A%3A%20CodeGen__2006-05-19-SingleEltReturn.c

llvm-svn: 299878
2017-04-10 20:34:19 +00:00
Reid Kleckner 324c99dee5 [IR] Make AttributeSetNode public, avoid temporary AttributeList copies
Summary:
AttributeList::get(Fn|Ret|Param)Attributes no longer creates a temporary
AttributeList just to hide the AttributeSetNode type.

I've also added a factory method to create AttributeLists from a
parallel array of AttributeSetNodes. I think this simplifies
construction of AttributeLists when rewriting function prototypes.
Previously we would test if a particular index had attributes, and
conditionally add a temporary attribute list to a vector. Now the
attribute set vector is parallel to the argument vector already that
these passes already construct.

My long term vision is to wrap AttributeSetNode* inside an AttributeSet
type that holds the enum attributes, but that will come in a follow up
change.

I haven't done any performance measurements for this change because
profiling hasn't shown that any of the affected code is hot.

Reviewers: pete, chandlerc, sanjoy, hfinkel

Reviewed By: pete

Subscribers: jfb, llvm-commits

Differential Revision: https://reviews.llvm.org/D31198

llvm-svn: 299875
2017-04-10 20:18:10 +00:00
Reid Kleckner b518054b87 Rename AttributeSet to AttributeList
Summary:
This class is a list of AttributeSetNodes corresponding the function
prototype of a call or function declaration. This class used to be
called ParamAttrListPtr, then AttrListPtr, then AttributeSet. It is
typically accessed by parameter and return value index, so
"AttributeList" seems like a more intuitive name.

Rename AttributeSetImpl to AttributeListImpl to follow suit.

It's useful to rename this class so that we can rename AttributeSetNode
to AttributeSet later. AttributeSet is the set of attributes that apply
to a single function, argument, or return value.

Reviewers: sanjoy, javed.absar, chandlerc, pete

Reviewed By: pete

Subscribers: pete, jholewinski, arsenm, dschuff, mehdi_amini, jfb, nhaehnle, sbc100, void, llvm-commits

Differential Revision: https://reviews.llvm.org/D31102

llvm-svn: 298393
2017-03-21 16:57:19 +00:00
Sean Silva 9011aca5f4 Use const-ref in range-loop for to avoid copying pairs of std::string
No reason to create temporaries.

Differential Revision: https://reviews.llvm.org/D29871

Patch by sergio.martins!

llvm-svn: 295807
2017-02-22 06:34:04 +00:00
Eugene Zelenko deaf695138 [IR] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 295383
2017-02-17 00:00:09 +00:00
Matthias Braun 8c209aa877 Cleanup dump() functions.
We had various variants of defining dump() functions in LLVM. Normalize
them (this should just consistently implement the things discussed in
http://lists.llvm.org/pipermail/cfe-dev/2014-January/034323.html

For reference:
- Public headers should just declare the dump() method but not use
  LLVM_DUMP_METHOD or #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
- The definition of a dump method should look like this:
  #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
  LLVM_DUMP_METHOD void MyClass::dump() {
    // print stuff to dbgs()...
  }
  #endif

llvm-svn: 293359
2017-01-28 02:02:38 +00:00
Amaury Sechet 74084c44ca Kill deprecated attribute API
Summary:
This kill various depreacated API related to attribute :
 - The deprecated C API attribute based on LLVMAttribute enum.
 - The Raw attribute set format (planned to be removed in 4.0).

Reviewers: bkramer, echristo, mehdi_amini, void

Subscribers: mehdi_amini, llvm-commits

Differential Revision: https://reviews.llvm.org/D23039

llvm-svn: 286062
2016-11-06 07:48:46 +00:00
Amaury Sechet 5f04d819a5 Rationalise the attribute getter/setter methods on Function and CallSite.
Summary:
While woring on mapping attributes in the C API, it clearly appeared that the recent changes in the API on the C++ side left Function and Call/Invoke with an attribute API that grew in an ad hoc manner. This makes it difficult to work with it, because one doesn't know which overloads exists and which do not.

Make sure that getter/setter function exists for both enum and string version. Remove inconsistent getter/setter, unless they have many callsites.

This should make it easier to work with attributes in the future.

This doesn't change how attribute works.

Reviewers: bkramer, whitequark, mehdi_amini, void

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D21514

llvm-svn: 281019
2016-09-09 04:50:38 +00:00
Honggyu Kim 9eb6a10251 [IR] Properly handle escape characters in Attribute::getAsString()
If an attribute name has special characters such as '\01', it is not
properly printed in LLVM assembly language format.  Since the format
expects the special characters are printed as it is, it has to contain
escape characters to make it printable.

Before:
  attributes #0 = { ... "counting-function"="^A__gnu_mcount_nc" ...

After:
  attributes #0 = { ... "counting-function"="\01__gnu_mcount_nc" ...

Reviewers: hfinkel, rengolin, rjmccall, compnerd

Subscribers: nemanjai, mcrosier, hans, shenhan, majnemer, llvm-commits

Differential Revision: https://reviews.llvm.org/D23792

llvm-svn: 280357
2016-09-01 11:44:06 +00:00
George Burgess IV 381fc0ee3c Make some LLVM_CONSTEXPR variables const. NFC.
This patch changes LLVM_CONSTEXPR variable declarations to const
variable declarations, since LLVM_CONSTEXPR expands to nothing if the
current compiler doesn't support constexpr. In all of the changed
cases, it looks like the code intended the variable to be const instead
of sometimes-constexpr sometimes-not.

llvm-svn: 279696
2016-08-25 01:05:08 +00:00
David Majnemer 0a16c22846 Use range algorithms instead of unpacking begin/end
No functionality change is intended.

llvm-svn: 278417
2016-08-11 21:15:00 +00:00
Matt Arsenault 4ced16dd2e Fix -Wreturn-type with gcc 4.8 and libc++
llvm-svn: 275922
2016-07-18 22:12:46 +00:00
Hal Finkel e87ad547ef Add getReturnedArgOperand to Call/InvokeInst, CallSite
In order to make the optimizer smarter about using the 'returned' argument
attribute (generally, but motivated by my llvm.noalias intrinsic work), add a
utility function to Call/InvokeInst, and CallSite, to make it easy to get the
returned call argument (when one exists).

P.S. There is already an unfortunate amount of code duplication between
CallInst and InvokeInst, and this adds to it. We should probably clean that up
separately.

Differential Revision: http://reviews.llvm.org/D22204

llvm-svn: 275031
2016-07-10 23:01:32 +00:00
Nicolai Haehnle 84c9f9919a Add writeonly IR attribute
Summary:
This complements the earlier addition of IntrWriteMem and IntrWriteArgMem
LLVM intrinsic properties, see D18291.

Also start using the attribute for memset, memcpy, and memmove intrinsics,
and remove their special-casing in BasicAliasAnalysis.

Reviewers: reames, joker.eph

Subscribers: joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D18714

llvm-svn: 274485
2016-07-04 08:01:29 +00:00
Benjamin Kramer af28e7d6fa Apply clang-tidy's modernize-loop-convert to most of lib/IR.
Only minor manual fixes. No functionality change intended.

llvm-svn: 273813
2016-06-26 14:10:56 +00:00
Amaury Sechet 6100adfeb5 Add support for string attributes in the C API.
Summary: As per title. This completes the C API Attribute support.

Reviewers: Wallbraker, whitequark, echristo, rafael, jyknight

Subscribers: mehdi_amini

Differential Revision: http://reviews.llvm.org/D21365

llvm-svn: 272811
2016-06-15 17:50:39 +00:00
Amaury Sechet 24c84fd1be Rename AttributeSetImpl::NumAttrs and AttributeSetImpl::getNumAttributes to reflect that they work on slots rather than attributes. NFC
Summary: The current naming not only doesn't convey the meaning of what this does, but worse, it convey the wrong meaning. This was a major source of confusion understanding the code, so I'm applying the boy scout rule here and making it better after I leave.

Reviewers: void, bkramer, whitequark

Differential Revision: http://reviews.llvm.org/D21264

llvm-svn: 272725
2016-06-14 22:04:16 +00:00
Amaury Sechet 392638d7b1 Make sure attribute kind and attributes are named respectively Kind and Attr consistently. Historically they used to be the same the terminology is very confused in the codebase. NFC.
llvm-svn: 272704
2016-06-14 20:27:35 +00:00
Benjamin Kramer ea76b6fde2 Use 'auto' to avoid implicit copies.
td_type is std::pair<std::string, std::string>, but the map returns
elements of std::pair<const std::string, std::string>. In well-designed
languages like C++ that yields an implicit copy perfectly hidden by
constref's lifetime extension. Just use auto, the typedef obscured the
real type anyways.

Found with a little help from clang-tidy's
performance-implicit-cast-in-loop.

llvm-svn: 272519
2016-06-12 19:02:34 +00:00
George Burgess IV 4540ca36a0 Attempt to make buildbot happier with r266032.
Apparently std::numeric_limits<unsigned>::max() isn't constexpr
everywhere yet.

llvm-svn: 266034
2016-04-12 01:44:13 +00:00
George Burgess IV 278199f615 Add the allocsize attribute to LLVM.
`allocsize` is a function attribute that allows users to request that
LLVM treat arbitrary functions as allocation functions.

This patch makes LLVM accept the `allocsize` attribute, and makes
`@llvm.objectsize` recognize said attribute.

The review for this was split into two patches for ease of reviewing:
D18974 and D14933. As promised on the revisions, I'm landing both
patches as a single commit.

Differential Revision: http://reviews.llvm.org/D14933

llvm-svn: 266032
2016-04-12 01:05:35 +00:00
Evgeniy Stepanov f17120a85f [safestack] Add canary to unsafe stack frames
Add StackProtector to SafeStack. This adds limited protection against
data corruption in the caller frame. Current implementation treats
all stack protector levels as -fstack-protector-all.

llvm-svn: 266004
2016-04-11 22:27:48 +00:00
Reid Kleckner 7de6761561 Fix non-determinism in order of LLVM attributes
We were using array_pod_sort on an array of type 'Attribute', which
wraps a pointer to AttributeImpl. For the most part this didn't matter
because the printing code prints enum attributes in a defined order, but
integer attributes such as 'align' and 'dereferenceable' were not
ordered.

Furthermore, AttributeImpl::operator< was broken for integer attributes.
An integer attribute is a kind and an integer value, and both pieces
need to be compared.

By fixing the comparison operator, we can go back to std::sort, and
things look good now.  This should fix clang arm-swiftcall.c test
failures on Windows.

llvm-svn: 265361
2016-04-04 23:06:05 +00:00
Manman Ren 9bfd0d03e9 Swift Calling Convention: add swifterror attribute.
A ``swifterror`` attribute can be applied to a function parameter or an
AllocaInst.

This commit does not include any target-specific change. The target-specific
optimization will come as a follow-up patch.

Differential Revision: http://reviews.llvm.org/D18092

llvm-svn: 265189
2016-04-01 21:41:15 +00:00
Manman Ren f46262e0b7 Swift Calling Convention: add swiftself attribute.
Differential Revision: http://reviews.llvm.org/D17866

llvm-svn: 264754
2016-03-29 17:37:21 +00:00
Matthias Braun 3328281538 AttributeSetImpl: Summarize existing function attributes in a bitset.
The majority of attribute queries checks for the existence of an enum
attribute in the FunctionIndex slot. We only have 48 of those and can
therefore summarize them in an uint64_t bitset which measurably improves
compile time.

Differential Revision: http://reviews.llvm.org/D16618

llvm-svn: 259252
2016-01-29 22:25:19 +00:00
Matthias Braun 31eeb76f5e AttributeSetNode: Summarize existing attributes in a bitset.
The majority of queries just checks for the existince of an enum
attribute.  We only have 48 of those and can summaryiz them in an
uint64_t bitfield so we can avoid searching the list. This improves
"opt" compile time by 1-4% in my measurements.

Differential Revision: http://reviews.llvm.org/D16617

llvm-svn: 259251
2016-01-29 22:25:13 +00:00
Yaron Keren eb2a25467e Annotate dump() methods with LLVM_DUMP_METHOD, addressing Richard Smith r259192 post commit comment.
clang part in r259232, this is the LLVM part of the patch.

llvm-svn: 259240
2016-01-29 20:50:44 +00:00
Manuel Jacob 5d073c4508 Remove duplicate documentation in Attributes.cpp. NFC.
The documentation for these methods is already present in the header.

llvm-svn: 258648
2016-01-23 22:42:24 +00:00
Craig Topper e30b8ca149 Use std::is_sorted and std::none_of instead of manual loops. NFC
llvm-svn: 256719
2016-01-03 19:43:40 +00:00
Akira Hatanaka 1cb242eb13 Provide a way to specify inliner's attribute compatibility and merging.
This reapplies r256277 with two changes:

- In emitFnAttrCompatCheck, change FuncName's type to std::string to fix
  a use-after-free bug.
- Remove an unnecessary install-local target in lib/IR/Makefile. 

Original commit message for r252949:

Provide a way to specify inliner's attribute compatibility and merging
rules using table-gen. NFC.

This commit adds new classes CompatRule and MergeRule to Attributes.td,
which are used to generate code to check attribute compatibility and
merge attributes of the caller and callee.

rdar://problem/19836465

llvm-svn: 256304
2015-12-22 23:57:37 +00:00
Akira Hatanaka 9c05cc5670 Revert r256277 and r256279.
Some of the bots failed again.

llvm-svn: 256280
2015-12-22 20:29:09 +00:00
Akira Hatanaka a61deb249b Provide a way to specify inliner's attribute compatibility and merging.
This reapplies r252990 and r252949. I've added member function getKind
to the Attr classes which returns the enum or string of the attribute.

Original commit message for r252949:

Provide a way to specify inliner's attribute compatibility and merging
rules using table-gen. NFC.

This commit adds new classes CompatRule and MergeRule to Attributes.td,
which are used to generate code to check attribute compatibility and
merge attributes of the caller and callee.

rdar://problem/19836465

llvm-svn: 256277
2015-12-22 20:00:05 +00:00
Vaivaswatha Nagaraj fb3f4907c0 Add InaccessibleMemOnly and inaccessibleMemOrArgMemOnly attributes
Summary:
This patch introduces two new function attributes 

InaccessibleMemOnly: This attribute indicates that the function may only access memory that is not accessible by the program/IR being compiled. This is a weaker form of ReadNone.
inaccessibleMemOrArgMemOnly: This attribute indicates that the function may only access memory that is either not accessible by the program/IR being compiled, or is pointed to by its pointer arguments. This is a weaker form of  ArgMemOnly

Test cases have been updated. This revision uses this (d001932f3a) as reference.

Reviewers: jmolloy, hfinkel

Subscribers: reames, joker.eph, llvm-commits

Differential Revision: http://reviews.llvm.org/D15499

llvm-svn: 255778
2015-12-16 16:16:19 +00:00
George Burgess IV 500d3039d7 Minor cleanup of Attribute code. NFC.
llvm-svn: 255751
2015-12-16 05:21:02 +00:00
Akira Hatanaka 237916b537 [AttributeSet] Overload AttributeSet::addAttribute to reduce compile
time.

The new overloaded function is used when an attribute is added to a
large number of slots of an AttributeSet (for example, to function
parameters). This is much faster than calling AttributeSet::addAttribute
once per slot, because AttributeSet::getImpl (which calls
FoldingSet::FIndNodeOrInsertPos) is called only once per function
instead of once per slot.

With this commit, clang compiles a file which used to take over 22
minutes in just 13 seconds.

rdar://problem/23581000

Differential Revision: http://reviews.llvm.org/D15085

llvm-svn: 254491
2015-12-02 06:58:49 +00:00
Pete Cooper 67cf9a723b Revert "Change memcpy/memset/memmove to have dest and source alignments."
This reverts commit r253511.

This likely broke the bots in
http://lab.llvm.org:8011/builders/clang-ppc64-elf-linux2/builds/20202
http://bb.pgr.jp/builders/clang-3stage-i686-linux/builds/3787

llvm-svn: 253543
2015-11-19 05:56:52 +00:00
Pete Cooper 72bc23ef02 Change memcpy/memset/memmove to have dest and source alignments.
Note, this was reviewed (and more details are in) http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html

These intrinsics currently have an explicit alignment argument which is
required to be a constant integer.  It represents the alignment of the
source and dest, and so must be the minimum of those.

This change allows source and dest to each have their own alignments
by using the alignment attribute on their arguments.  The alignment
argument itself is removed.

There are a few places in the code for which the code needs to be
checked by an expert as to whether using only src/dest alignment is
safe.  For those places, they currently take the minimum of src/dest
alignments which matches the current behaviour.

For example, code which used to read:
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* %src, i32 500, i32 8, i1 false)
will now read:
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 8 %dest, i8* align 8 %src, i32 500, i1 false)

For out of tree owners, I was able to strip alignment from calls using sed by replacing:
  (call.*llvm\.memset.*)i32\ [0-9]*\,\ i1 false\)
with:
  $1i1 false)

and similarly for memmove and memcpy.

I then added back in alignment to test cases which needed it.

A similar commit will be made to clang which actually has many differences in alignment as now
IRBuilder can generate different source/dest alignments on calls.

In IRBuilder itself, a new argument was added.  Instead of calling:
  CreateMemCpy(Dst, Src, getInt64(Size), DstAlign, /* isVolatile */ false)
you now call
  CreateMemCpy(Dst, Src, getInt64(Size), DstAlign, SrcAlign, /* isVolatile */ false)

There is a temporary class (IntegerAlignment) which takes the source alignment and rejects
implicit conversion from bool.  This is to prevent isVolatile here from passing its default
parameter to the source alignment.

Note, changes in future can now be made to codegen.  I didn't change anything here, but this
change should enable better memcpy code sequences.

Reviewed by Hal Finkel.

llvm-svn: 253511
2015-11-18 22:17:24 +00:00
Akira Hatanaka 5af7ace4ee Revert r252990.
Some of the buildbots are still failing.

llvm-svn: 252999
2015-11-13 01:44:32 +00:00
Akira Hatanaka c7dfb76fe7 Provide a way to specify inliner's attribute compatibility and merging.
This reapplies r252949. I've changed the type of FuncName to be
std::string instead of StringRef in emitFnAttrCompatCheck.

Original commit message for r252949:

Provide a way to specify inliner's attribute compatibility and merging
rules using table-gen. NFC.

This commit adds new classes CompatRule and MergeRule to Attributes.td,
which are used to generate code to check attribute compatibility and
merge attributes of the caller and callee.

rdar://problem/19836465

llvm-svn: 252990
2015-11-13 01:23:11 +00:00
Akira Hatanaka f3aa82f666 Revert r252949.
It broke some of the bots including clang-x64-ninja-win7.

llvm-svn: 252951
2015-11-12 21:19:18 +00:00
Akira Hatanaka 61b81a563a Provide a way to specify inliner's attribute compatibility and merging
rules using table-gen. NFC.

This commit adds new classes CompatRule and MergeRule to Attributes.td,
which are used to generate code to check attribute compatibility and
merge attributes of the caller and callee.

rdar://problem/19836465

llvm-svn: 252949
2015-11-12 20:59:43 +00:00
James Molloy e6f87ca812 Add a new attribute: norecurse
This attribute allows the compiler to assume that the function never recurses into itself, either directly or indirectly (transitively). This can be used among other things to demote global variables to locals.

llvm-svn: 252282
2015-11-06 10:32:53 +00:00
Sanjoy Das 88d0fdeb00 [IR] Have AttrBuilder::clear clear `TargetDepAttrs`.
Test case attached -- currently the parser smears the "foo bar" to all
of the formal arguments.

llvm-svn: 246812
2015-09-03 22:27:42 +00:00
James Y Knight aa365b2fcd Add a TrailingObjects template class.
This is intended to help support the idiom of a class that has some
other objects (or multiple arrays of different types of objects)
appended on the end, which is used quite heavily in clang.

Differential Revision: http://reviews.llvm.org/D11272

llvm-svn: 244164
2015-08-05 22:57:34 +00:00
Craig Topper e3dcce9700 De-constify pointers to Type since they can't be modified. NFC
This was already done in most places a while ago. This just fixes the ones that crept in over time.

llvm-svn: 243842
2015-08-01 22:20:21 +00:00
Igor Laevsky 39d662f7ba Add argmemonly attribute.
This change adds new attribute called "argmemonly". Function marked with this attribute can only access memory through it's argument pointers. This attribute directly corresponds to the "OnlyAccessesArgumentPointees" ModRef behaviour in alias analysis.

Differential Revision: http://reviews.llvm.org/D10398

llvm-svn: 241979
2015-07-11 10:30:36 +00:00
Peter Collingbourne 82437bf7a5 Protection against stack-based memory corruption errors using SafeStack
This patch adds the safe stack instrumentation pass to LLVM, which separates
the program stack into a safe stack, which stores return addresses, register
spills, and local variables that are statically verified to be accessed
in a safe way, and the unsafe stack, which stores everything else. Such
separation makes it much harder for an attacker to corrupt objects on the
safe stack, including function pointers stored in spilled registers and
return addresses. You can find more information about the safe stack, as
well as other parts of or control-flow hijack protection technique in our
OSDI paper on code-pointer integrity (http://dslab.epfl.ch/pubs/cpi.pdf)
and our project website (http://levee.epfl.ch).

The overhead of our implementation of the safe stack is very close to zero
(0.01% on the Phoronix benchmarks). This is lower than the overhead of
stack cookies, which are supported by LLVM and are commonly used today,
yet the security guarantees of the safe stack are strictly stronger than
stack cookies. In some cases, the safe stack improves performance due to
better cache locality.

Our current implementation of the safe stack is stable and robust, we
used it to recompile multiple projects on Linux including Chromium, and
we also recompiled the entire FreeBSD user-space system and more than 100
packages. We ran unit tests on the FreeBSD system and many of the packages
and observed no errors caused by the safe stack. The safe stack is also fully
binary compatible with non-instrumented code and can be applied to parts of
a program selectively.

This patch is our implementation of the safe stack on top of LLVM. The
patches make the following changes:

- Add the safestack function attribute, similar to the ssp, sspstrong and
  sspreq attributes.

- Add the SafeStack instrumentation pass that applies the safe stack to all
  functions that have the safestack attribute. This pass moves all unsafe local
  variables to the unsafe stack with a separate stack pointer, whereas all
  safe variables remain on the regular stack that is managed by LLVM as usual.

- Invoke the pass as the last stage before code generation (at the same time
  the existing cookie-based stack protector pass is invoked).

- Add unit tests for the safe stack.

Original patch by Volodymyr Kuznetsov and others at the Dependable Systems
Lab at EPFL; updates and upstreaming by myself.

Differential Revision: http://reviews.llvm.org/D6094

llvm-svn: 239761
2015-06-15 21:07:11 +00:00